Place room temperature butter in a small saute pan or saucepan over very low heat. Slowly whisk in flour until very smooth. Continue whisking until the roux begins to brown. Add the onion and celery. Cook for 5 minutes. Add the stock and stir. Simmer for 10 minutes. Add remaining ingredients (except filé and salt) and return to a simmer. Adjust salt to taste. If you are adding seafood, add it at the very end and make sure it is completely cooked. Add filé. Mix well and serve over rice.